[keepalived] fix netmask for vip
[keepalived] fix netmask for vip

For pacemaker we ensure netmask of virtual IP to 64bit for IPv6 and
32bit for IPv4. We should have feature parity in keepalived setup.[1]
The issue is that puppet picks first IP orf ifconfig output as and
interface IP. In case of IPv6 keepalived would add new IP to
interface with netmask 128 causing interface_for_ip to fail on
second puppet run.

[1] - https://github.com/openstack/puppet-tripleo/blob/master/manifests/pacemaker/haproxy_with_vip.pp

Closes-Bug: #1659309

Change-Id: Icb0c9a8d51a9bfcdc4b2caef9e52fdeb6f634cba

openstack/puppet-tripleo,openstack/puppet-tripleo,openstack/puppet-tripleo